The statements in this section merely provide background information related to the present disclosure and do not constitute prior art.
Recently, a VoIP voice data frame is encoded using an Application Layer Forward Error Correction (AL-FEC) code and then transmitted to a reception side to compensate for loss during transmission.
For example, a transmission side generates and outputs the VoIP voice data in the unit of one frame per 20 ms and immediately transmitted to the reception side via a lower layer.
However, when encoding using AL-FEC codes are applied, after a certain quantity of VoIP voice data frames which are output in units of 20 ms are collected, the collected data frames are encoded and the encoded data (encoded data packets) are generated and output by a transmission side.
To explain in more detail with reference to FIG. 1, in case where encoding using AL-FEC codes are applied, when a voice codec of the transmission side generates and output voice data frames every 20 ms, the transmission side collects the predetermined number K (for example, 4) of voice data frames to be encoded, encodes the collected voice data frames, and then generates and outputs the particular number N (for example, 8) of encoded data packets which have been encoded. Then, the output encoded data packets are continuously transmitted to a reception side. The inventor(s) has experienced that this continuous transmission results in a concatenation loss of channels. The inventor(s) has noted that this is because there is a concern that the continuous loss will cause all the continuously transmitted encoded data packets to be lost.